There has been typically known a hybrid construction machine configured such that an engine drives a power generator and a hydraulic pump, the power generator generates electric power to drive an electric rotating motor that rotates an upper revolving body, and the hydraulic pump supplies pressure oil to drive a hydraulic actuator of working equipment and a hydraulic motor of a carrier.
In such a hybrid construction machine, electric devices to be installed (e.g., a power generator and an inverter, and an electric rotating motor and an inverter) are electrically connected to each other by a power cable (see, for instance, Patent Literature 1). FIG. 6 shows a connector 200 used for connection between the power cable 10 and the electric devices.
The connector 200 includes: a device socket 21 to be attached to an electric device; and a cable plug 220 to be attached to the power cable 10. The connector 200 includes a detection switch 30 for judging a fitting condition of the device socket 21 and the cable plug 220 (FIG. 6 shows an unfitting condition).
The detection switch 30 includes: a pair of contact terminals 31, 31 provided to the device socket 21; and a contact conductor 221 provided to the cable plug 220. In a fitting condition of the device socket 21 and the cable plug 220, the contact terminals 31, 31 are in contact with a contact surface 221A of the contact conductor 221 (i.e., a back surface of the contact conductor 221 in the figure), and the device socket 21 and the cable plug 220 are electrically conducted through the contact surface 221A. Based on an electrically conducting condition between the contact terminals 31, 31 obtained by the detection switch 30, a fitting condition of the connector 200 can be confirmed.
In the connector 200 disclosed in Patent Literature 1, the contact conductor 221 is attached to a cover plate 223 through an insulative plate 222, and the cover plate 223 is attached to a plug housing 224. In this arrangement, the cover plate 223 and the plug housing 224 are conductive, and plug housing 224 is electrically grounded by being fitted to the device socket 21. Accordingly, since the contact conductor 221 is insulated only by the insulative plate 222 in this arrangement, a long electrical clearance cannot be obtained. Depending on situations, the contact conductor 221 may short-circuit to the plug housing 224 through the cover plate 223. For this reason, typically, the cover plate 223 and the contact conductor 221 (except for the contact surface 221A) are respectively coated with insulative coatings 225 and 226 to improve insulation performance.